Detecting and tracking the condition of a road, lane, or trail is a challenge in developing intelligent driver safety systems (IDSS) and advanced driver assistance systems (ADAS), as well as in robotic unmanned ground vehicles (UGVs). Prior approaches have had particular difficulty detecting edges of such roads, lanes, and trails when their edges are imprecise or not well defined. Failure to correctly determine such an edge in these types of systems may lead to degraded performance, incorrect navigation, or unplanned departure from the road, lane, or trail.